Preheat the oven to 180 degree for ten mins.
Then peel the banana and mash it in a bowl very well.
Now add vanilla, sugar and oil to it and mix it very well.
Keep it aside.
In the another bowl, add flour, baking soda, baking powder and whisk it properly.
After mixing, make a hole in between or dent and pour the banana mixture in it.
Now cut and fold but do not over mix the mixture.
But mix it properly by adding chopped walnuts and raisins, but keep some walnuts for sprinkling on the top.
Now keep the paper liners in the muffin tray.
Now take spoon of the batter and pour upto 3/4 th of the liners.
Top with some chopped walnut over it.
Bake for 30 mins.
After that check it by inserting the toothpick.
If it comes out clean and top turns golden brown then it is done.
